1. Field of the Invention
The present invention relates to a feed apparatus to render a manual or automatic feed movement to a table of a machine tool.
2. Description of the Prior Art
In the past, in order to change over the mode of operation of feed apparatus for machine tool tables between manual and automatic feeds, the end chambers of a cylinder connected to the table have been communicated with each other or communicated to a pressure fluid supply source and a reservoir by means of a change-over valve.
Furthermore, in order to set the feed speed in the automatic feed mode, a throttle valve has been provided in a passage communicating with the reservoir. Therefore, a change-over valve and a throttle valve have been separately required, resulting in expensive installation.